Elevating lift with a stabilized movable base

ABSTRACT

The elevating lift with a stabilized movable base includes a base with extendable legs that provide minimum to maximum adjustable stability during use and transport. A lift system is mounted on the base, and a platform assembly is mounted on top of the lift system for selective raising or lowering. Each extendable leg supports a caster, rendering the base movable, and selective extension and retraction of the legs adjusts the stability of the lift. The plurality of legs can be further driven to simultaneously rotate about the vertical axis to steer the lift. The stabilized movable base is further alternatively used in combination with a stool, providing minimum to maximum stability during use and transport of seating, and multiple elevating lifts may be used to support linked platform assemblies in various configurations.

BACKGROUND 1. Field

The disclosure of the present patent application relates to liftdevices, and particularly to an elevating lift with a stabilized movablebase, allowing for simultaneous and stable deployment and collapse ofstabilizing legs.

2. Description of the Related Art

Many lifting devices exist to assist users to gain access to elevatedareas difficult to reach through most conventional means, such asstretching towards maximum reach of the user's physical ability,ladders, and the like. In the case of manual reaching, any activityperformed while stretching to reach the desired area is rather limitedby the user's physical endurance in maintaining the stretched position.Most ladders, while useful, tend to be rather lackluster in terms ofstability due to their design and function where the ladder leansagainst a surface with only the legs and abutting portions providing thenecessary stability. Depending on the extent of the ground surfacelevel, the stability of a ladder may be compromised if the groundsurface is uneven, which requires buttressing by additional features onthe ladder or an additional person.

Powered lifters are also available for more heavy duty or industrialapplications. These types of devices provide great utility due to theweight that can be supported, which allows for a larger amount ofsupplies, tools, and/or cargo to be carried, since they have arelatively large base supporting the platform and lift system. However,these types of lifters tend to be rather large, employ relativelycomplex lift systems, such as a scissor lift, and/or utilize a singletelescoping mast that may lose structural integrity or provide reducedstability over time. Moreover, most of these power lifters tend to beunsuitable for personal applications due to the relatively large andcumbersome design. In light of the above, it would be a benefit in theart of lift devices to provide a lift of suitable size and configurationfor personal use with a relatively robust and simple lift system. Thus,an elevating lift with a stabilized movable base solving theaforementioned problems is desired.

SUMMARY

The elevating lift with a stabilized movable base includes a base withextendable legs that provide minimum to maximum adjustable stabilityduring use and transport. The elevating lift with a stabilized movablebase includes a movable base, having opposed upper and lower surfaces,and a housing mounted on the upper surface of the movable base. Thehousing has an open upper end and at least one sidewall. A telescopingcage assembly is further provided. The lower end of the telescoping cageassembly is secured within the housing. A platform assembly is mountedon the upper end of the telescoping cage assembly.

An annular collar is slidably mounted about the housing. A plurality ofupper mounts and a plurality of lower mounts are each disposed on theannular collar. A plurality of legs are further provided. Each legincludes an upper bar, having opposed upper and lower ends, the upperend being pivotally secured to a respective one of the plurality ofupper mounts. Each leg further includes a lower bar, having opposedupper and lower ends, the upper end being pivotally secured to arespective one of the plurality of lower mounts. A hollow leg housingreceives and covers the upper and lower bars.

A plurality of casters are also provided, the lower ends of the upperand lower bars being respectively pivotally secured to a correspondingcaster support of each caster. The elevating lift with a stabilizedmovable base further includes a plurality of struts, each having opposedupper and lower ends. The upper end of each strut is pivotally securedto a central portion of a corresponding one of the plurality of legs.The lower end of each strut is pivotally secured to a lower end of thehousing.

In an alternative embodiment, additional simultaneous, selectiverotational movement of the legs is provided. In this embodiment, theelevating lift with a stabilized movable base further includes aneccentric collar slidably mounted about the housing above the annularcollar. A rotating cuff is mounted about the housing above the eccentriccollar. The rotating cuff is fixedly secured to the eccentric collar,the rotating cuff being selectively rotatable about the housing. Aplurality of auxiliary mounts are disposed on the eccentric collar. Aplurality of auxiliary bars are further provided, each auxiliary barhaving opposed upper and lower ends. The upper end is pivotally securedto a respective one of the plurality of auxiliary mounts, and the lowerend is pivotally secured to a respective one of the caster supports ofthe plurality of casters. In this embodiment, further rotational freedomabout the vertical axis is possible. A rotational linkage is provided.The rotational linkage links the lower end of the auxiliary bar to thecaster support, driving simultaneous rotation of all casters inparallel, allowing all casters to be simultaneously steered in the samedirection.

In a further alternative embodiment, the stabilizing base is used incombination with a stool. The stool includes a movable base havingopposed upper and lower surfaces. A vertical support replaces thetelescoping cage assembly of the previous embodiments, the verticalsupport having an upper end and a lower end. The lower end is mounted onthe movable base. A seat replaces the platform assembly of the previousembodiments and is mounted on the upper end of the vertical support.

An annular collar is slidably mounted about the vertical support. Aplurality of upper mounts and a plurality of lower mounts are disposedon the annular collar. A plurality of legs are further provided, eachleg including an upper bar having opposed upper and lower ends, theupper end being pivotally secured to a respective one of the pluralityof upper mounts. Each leg further includes a lower bar having opposedupper and lower ends, the upper end being pivotally secured to arespective one of the plurality of lower mounts. A hollow leg housingcovers the upper and lower bars.

A plurality of casters are provided, the lower ends of the upper andlower bars being respectively pivotally secured to a correspondingcaster support of each caster. Similar to the previous embodiments, aplurality of struts are also provided, each strut having opposed upperand lower ends. The upper end of each strut is pivotally secured to acentral portion of a corresponding one of the plurality of legs, and thelower end of each strut is pivotally secured to the movable base.

Similar to the previous embodiment, in which simultaneous rotation ofthe legs is effected, an eccentric collar is slidably mounted about thevertical support above the annular collar. A plurality of auxiliarymounts are disposed on the eccentric collar. A plurality of auxiliarybars are further provided, each having opposed upper and lower ends. Theupper end is pivotally secured to a respective one of the plurality ofauxiliary mounts, and the lower end is pivotally secured to a respectiveone of the caster supports of the plurality of casters. In thisembodiment, further rotational freedom about the vertical axis ispossible, with a rotational linkage being provided. The rotationallinkage links the lower end of the auxiliary bar to the caster support,driving simultaneous rotation of all casters in parallel, allowing allcasters to be simultaneously steered in the same direction

These and other features of the present disclosure will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of an elevating liftwith a stabilized movable base, shown in a deployed configuration.

FIG. 2 is a perspective view of the elevating lift of FIG. 1, shown in aretracted configuration.

FIG. 3 is a partial perspective view of the elevating lift of FIG. 1.

FIG. 4 is a perspective view of a caster assembly of the elevating liftof FIG. 1.

FIG. 5 is a partial perspective view of an alternative embodiment of anelevating lift with a stabilized movable base.

FIG. 6 is a perspective view of a telescoping cage assembly of theelevating lift of FIG. 5.

FIG. 7 is a partial perspective view of a support column of thetelescoping cage assembly of FIG. 6.

FIG. 8 is a perspective view of another alternative embodiment of theelevating lift with a stabilized movable base.

FIG. 9 is a perspective view of an alternative configuration of theelevating lift with a stabilized movable base of FIG. 8.

FIG. 10 is a perspective view of the elevating lift with a stabilizedmovable base of FIG. 8.

FIG. 11 is a perspective view of a stool having an elevating lift with astabilized movable base.

FIG. 12 is an exploded partial perspective view of the stool of FIG. 11.

FIG. 13 is a partial perspective view of another alternative embodimentof an elevating lift with a stabilized movable base.

FIG. 14 is a partial perspective view of the elevating lift of FIG. 13.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIGS. 1 and 2, the elevating lift with a stabilized movablebase, designated generally as 10, includes a stabilizer base assembly20, a selectively extendable lift system 30 extending upward from thestabilizer base assembly 20, and a platform assembly 70 coupled to thetop of the lift system 30. The stabilizer base assembly 20 supports thelift system 30 and includes a movable base 21. A plurality ofselectively extendable casters 24 are coupled to the movable base 21 toenable selective transport of the elevating lift 10 to a desiredlocation. Although the movable base 21 is shown as being generallycircular, it should be understood that the movable base 21 may have anydesired or required shape or relative dimensions, depending on theparticular application.

The platform assembly 70 provides space to support a user and anynecessary supplies and equipment. The platform assembly 70 includes aplatform base 71, a level platform 72, and a guardrail assembly 75. Asshown, the platform base 71 may be configured as an elongate sleevecovering the height of a telescoping cage assembly 40 when in acollapsed state, as shown in FIG. 2. As shown in FIGS. 1 and 2, ahousing 12 having an open upper end 14 is mounted on the movable base21. When in the collapsed state of FIG. 2, the telescoping cage assembly40 and at least a lower portion of platform base 71 are received withinan open interior region of the housing 12. The telescoping cage assembly40 may be any suitable type of telescopic support used in elevatinglifts, as are well known in the art. An example of such a telescopingsupport is shown in U.S. Pat. No. 9,701,525 (the '525 patent), which ishereby incorporated by reference in its entirety.

The platform 72 is constructed to provide at least two degrees ofadjustable positioning movement, the first being elevated positioningvia selective extension and retraction of the telescoping cage assembly40, and the second being rotational or angular positioning about thecentral axis of the lift system 30. This enables the user to set thedesired height and rotation as required to reach the work area. Althougha disc shape is preferred, the platform 72 may be constructed in anyshape suitable for supporting a user(s), supplies and/or equipment,e.g., square, rectangular, and other geometric shapes. One or more mountcollars 73 extend radially from the periphery of the platform 72 toenable slidable mounting of the guardrail assembly 75.

The stabilizer base assembly 20 supports the lift system 30, and thelift system 30 extends axially therefrom. The lift system 30 enablesselective, positive elevation of the platform assembly 70 between thelowermost position, shown in FIG. 2, the highest position, shown in FIG.1, and any position therebetween. As is well known in the art, and asshown in the exemplary system of the '525 patent, the lift system 30includes the telescoping cage assembly 40, a drive assembly, and a drivetrain coupled to the telescoping cage assembly 40, the drive assemblyfacilitating raising and lowering of the platform assembly 70 uponselective activation of the drive assembly. A spring 16, shock absorber,support or the like is provided to prevent excessive downward movementof platform assembly 70 during collapsing of the elevating lift 10.

As shown in FIGS. 1 and 2, an annular collar 18 is slidably mountedabout the housing 12. Vertical positioning of the annular collar 18 isselectively controllable by a linear actuator 19 or the like, which maybe controlled by any suitable type of user interface, such as exemplarycontrol box 22. As best seen in FIG. 2, a plurality of legs 26 areprovided for supporting the casters 24. Each leg 26 has an upper end 28,which is pivotally secured to the annular collar 18, and a lower end30′, which is pivotally attached to a respective one of the casters 24.A plurality of struts 32 are further provided, each strut 32 having anupper end 34 and a lower end 36. The upper end 34 of each strut 32 ispivotally secured to a corresponding one of the legs 26, and the lowerend 36 of each strut 32 is pivotally secured to the movable base 21.

In use, as the linear actuator 19 pushes the annular collar 18 downward,the downward movement of the collar 18 causes the legs 26 to extendradially outward, increasing the area of the support base defined by thecasters 24. For purposes of simplification and clarity, FIG. 3 showsonly a single leg 26 secured to the housing 12 on the movable base 21.As shown in FIG. 3, each leg 26 preferably includes an upper bar 44 anda lower bar 46, which are preferably contained within a protectivehousing 42. For each leg 26, corresponding upper and lower mounts 48,52, respectively, are secured to the annular collar 18. The upper end 66of the upper bar 44 is pivotally secured to the upper mount 48, and theupper end 80 of the lower bar 46 is pivotally secured to the lower mount52. The lower ends 68, 82 of the respective upper and lower bars 44, 46are each pivotally secured to a swivel caster head 54 of a correspondingcaster 24. The swivel head of each caster 24 includes a vertical stemhaving a transverse bore defined therein for insertion of a pivot pinconnecting the lower end of the upper bar to the caster 24, and a knobor lug extending perpendicular to the base of the stem, the lug alsohaving a transverse bore defined therein for insertion of a pivot pinconnecting the lower end of the lower bar to the caster 24. Thus, theinternal structure of each leg 26 defines a four-bar parallelogramlinkage, the upper and lower bars 44. 46 being one pair of parallellinks, the annular collar 18 between the collar mounts 48, 52, and theswivel caster head 54 being the other pair of parallel links. Thefour-bar parallelogram linkage keeps the stems of the swivel casterassemblies 24 vertical as the legs 26 extend and retract, since there isno fixed structure similar to, e.g., a rigid vertical chair leg, aplatform, etc. that the stem of the caster 24 can be inserted into tokeep the swivel fork vertical when the legs 26 are retracted andextended. The legs 26 pivot between a nearly vertical position fortransport and storage, and a nearly horizontal position when thetelescoping cage 40 is extended to raise the platform 70 to maximumheight, the horizontal position providing maximum stability. Mounts 64are provided on the lower end of the housing 12 for pivotal attachmentof the lower ends 36 of the struts 32, as shown. For maximum extensionof the legs 26, a plurality of slots or recess 62 may be defined in themovable base 21, as shown, allowing for horizontal, or near horizontal,extension of the legs 26 in the radial direction.

As shown in FIG. 4, a locking disc 90 is preferably provided for eachcaster 24, allowing for selectively controlled locking of each caster24. Each locking disc 90 has a plurality of slots or recesses 92 formedin the circumference, as shown. The locking disc 90 is mounted on oneside of the wheel hub of the caster 24 and is fixed with respectthereto, such that the locking disc 90 rotates (or ceases to rotate)with the wheel hub. An electric motor screw linear actuator 94 or thelike is mounted on a side panel 96 of the steering yoke 98. In order tolock the caster 24 in place, the screw linear actuator 94 pushes itslocking head 100 through one of the slots 92 to prevent rotation of thecaster 24. The electric motor screw linear actuator 94 may be under usercontrol via control box 22 or the like.

The alternative embodiment of FIGS. 13 and 14 is similar to that of theembodiment of FIGS. 1-4. However, as shown, the housing 12 of theprevious embodiment has been replaced by a plurality of verticallyextending tubes 13, each having an upper end 15 and a lower end 17. Thelower ends 17 of the vertically extending tubes 13 are mounted on themovable base 21, similar to the mounting of housing 12 on the movablebase 21. The upper ends 15 of the vertically extending tubes 13 aresecured together by an annular retainer 23, as shown, and the annularcollar 18 is replaced by a sliding collar 25 in the embodiment of FIGS.13 and 14. A plurality of cuffs 27 extend from the sliding collar 25,the plurality of vertically extending tubes 13 being slidable in thecuffs 27, respectively, thus allowing the sliding collar 25 to stablyslide up and down with respect to the plurality of vertically extendingtubes 13.

The respective upper ends 28 of the plurality of legs 26 are eachpivotally secured to the sliding collar 25 in a manner similar to thatof the embodiment of FIGS. 1-4. As best seen in FIG. 14, whereas theplurality of upper mounts 48 and the plurality of lower mounts 52 weresecured to the annular collar 18, each of the cuffs 27 in the embodimentof FIGS. 13 and 14 has an upper mount 48 and a lower mount 52 securedthereto. For purposes of simplification and clarity, FIG. 14 shows onlya single leg 26 secured to the plurality of vertically extending tubes13 and movable base 21. The lower ends 30′ of the plurality of legs 26are each rotatably secured to a respective one of the casters 24, as inthe previous embodiment.

In this embodiment, a plurality of struts 32 are provided, each strut 32having an upper end 34 and a lower end 36. The upper end 34 of eachstrut 32 is pivotally secured to a corresponding one of the legs 26, andthe lower end 36 of each strut 32 is pivotally secured to the movablebase 21. Mounts 64 are respectively provided on the lower ends 17 of thevertically extending tubes 13 for pivotal attachment of the lower ends36 of the struts 32.

In the embodiment of FIGS. 1-4, the linear actuator 19 pushed theannular collar 18 downward, and the downward movement of the collar 18caused the legs 26 to extend radially outward, increasing the area ofthe support base defined by the casters 24. However, in the embodimentof FIGS. 13 and 14, the linear actuator 19 is replaced by linearactuator 29, which has an upper end 31 pivotally secured to one of thelegs 26, and a lower end 33 pivotally secured to the movable base 21.Extension of the linear actuator 29 causes each leg 26 to slide downwardsimultaneously, due to the upper end 28 of each of the legs 26 beingsecured to the sliding collar 25. Similarly, contraction of the linearactuator 29 causes each leg 26 to slide upward simultaneously. Thelinear actuator 29 may be controlled by any suitable type of userinterface, such as the exemplary control box 22. For maximum extensionof the legs 26, a plurality of slots or recesses 62 may be defined inthe movable base 21, as shown, allowing for horizontal, or nearhorizontal, extension of the legs 26 in the radial direction.

The telescoping cage assembly 40 is best shown in FIG. 6. Thetelescoping cage assembly 40 includes a first telescoping cage 141, asecond telescoping cage 144 slidably coupled to the first telescopingcage 141, and a third telescoping cage 147 slidably coupled to thesecond telescoping cage 144. Each of the first, second, and thirdtelescoping cages 141, 144, 147 forms a generally cage-typeconfiguration. The first telescoping cage 141 includes an endcap 142 a,forming a base for the cage assembly 40. The endcap 142 a is preferablya circular plate, although other geometrically shaped plates and/orspoked plates may be used. A central opening 42 c permits parts of thedrive assembly to extend therethrough. A plurality of elongated,angularly spaced, first support columns 143 extend axially from one faceof the endcap 142 a to form a generally cylindrical cage shape. Thefirst support columns 143 are preferably hollow pipes of equal length.

The second telescoping cage 144 includes a first endcap 145 a and asecond endcap 145 b spaced from the first endcap 145 a. Each of theendcaps 145 a, 145 b is preferably a circular plate, although othergeometrically shaped plates and/or spoked plates may be used. Aconcentric hole 145 c is formed through each endcap 145 a, 145 b topermit parts of the drive assembly to extend therethrough and residetherein when in the normal unelevated state of FIG. 2. A plurality ofelongated, angularly spaced, second support columns 146 extend axiallybetween the first endcap 145 a and the second endcap 145 b to form ageneral, cylindrical cage shape. The second support columns 146 arepreferably hollow pipes of equal length.

The third telescoping cage 147 is defined by endcap 145 b and an upperendcap 148 a. A central opening 148 c is formed in endcap 148 a topermit parts of the drive assembly to extend therethrough and residetherein when in the normal un-elevated state shown in FIG. 2. Aplurality of elongated, angularly spaced, third support columns 149extend axially between the endcap 145 b and the upper endcap 148 a toform a generally cylindrical cage shape. The support columns 419 arepreferably hollow pipes of equal length.

Preferably, the first, second and third support columns 143, 146, 149,respectively, are constructed in similar manner. FIG. 7 illustrates oneof the second support columns 146, although it should be understood thatthe first support columns 143 and the third support columns 149 arepreferably configured in a similar manner. As noted above, each supportis preferably hollow. As shown in FIG. 7, an internal sliding member 150is disposed within the support column 146, and drive lines 11 a, 11 bextend through the sliding member 150. The drive lines 11 a, 11 b areassociated with the drive train assembly that enables the telescopingcages 141, 144, 147 to reciprocate relative to one another.

Each of the first, second and third support columns 143, 146, 149preferably is an arcuate in cross section, being configured as a segmentof a circle, in order to enhance the rigidity of the structure toprevent bending or deformation. The first, second and third supportcolumns 143, 146, 149 may be formed from extruded aluminum or the like,and the internal sliding member 150 may be formed from steel or asimilar high-strength material.

In the alternative embodiment shown in FIG. 5, selective and controlledrotational movement of the casters 24 is provided, all of the casters 24being able to move simultaneously about the vertical axis defined by thehousing 12 and the movable base 21. A rotating cuff 110 is mounted aboutthe sidewall of housing 12 above the annular collar 18. The rotatingcuff 110 is secured to an eccentric collar 114, which is mounted aboutthe sidewall of housing 12 and above annular collar 18. The rotatingcuff 110 is rigidly secured to the eccentric collar 114, such thatrotation of the rotating cuff 110 about housing 12 causes the eccentriccollar 114 to similarly rotate.

As shown in FIG. 5, a bracket 116 is secured to the upper edge 118 ofthe housing 12. Similarly, a bracket 120 is secured to an upper end ofrotating cuff 110. A linear actuator 122 or the like is fixed to, andextends between, brackets 116, 120. Thus, through selective actuation oflinear actuator 122, rotating cuff 110 and eccentric collar 114 aredriven to rotate about housing 12. Similar to mounts 48, 52, anauxiliary mount 124 is secured to eccentric collar 114. The upper end126 of an auxiliary bar 112 is pivotally secured to auxiliary mount 124,and the lower end 128 of the auxiliary bar 112 is pivotally secured tothe caster support 54 of caster 24. Thus, as upper and lower bars 44, 46and strut 32 of each leg 26 guide and drive the extension andcontraction of each leg 26, the auxiliary bar 112, through itsconnection with eccentric collar 114, drives rotation of each leg 26about the vertical axis. In addition to the pivotal attachment of thelower end 128 to the caster support 54, the lower end 128 isadditionally rotationally adjustable through rotational linkage 130,i.e., the pivotal attachment of the lower end 128 of the auxiliary bar112 to the caster support 54 creates rotation of the leg 26 about ahorizontal axis during collapse and extension of legs 26, but furtherrotational freedom about the vertical axis is possible. Rotationallinkage 130, which links the lower end 128 to the caster support 54,drives simultaneous rotation of all casters 24 in parallel, allowing allcasters 24 to be simultaneously steered in the same direction.

In the embodiment of FIG. 8, the platform 72 is replaced by analternative platform 172. As shown, the platform 172 and correspondingguardrail assembly 175 are closed on one end and open on the other end.This allows a pair of the elevating lifts 10 to be joined together by abridge or connector 180, providing a raised walkway with greater surfacearea and stability than just the single elevating lift with a stabilizedmovable base 10. As shown in FIG. 9, a further alternative platform 190having a pair of opposed open ends may be used for connecting more thantwo of the elevating lifts 10. Here, the platforms 190 are positionedbetween pairs of bridges 180, although it should be understood that theplatforms 190 may also be positioned directly adjacent to the platforms172.

As shown in FIG. 10, a bearing seat 174 may be mounted on a lowersurface 176 of the platform 172. This allows for selective angularadjustment of the platform 172 with respect to its correspondingplatform base 71. Sliding, locking bolts 178 (adjusted through slidingmovement of handle portions 182 in respective slots 184) may be extendwithin slots or recesses 186 formed in the bridge 180 in order tosecurely lock the bridge 180 in place with respect to the platforms 172.It should be understood that a similar locking system may be used withplatforms 190 of FIG. 9. In the two-lift configuration of FIGS. 8 and10, the casters 24 and bearing seat 174 of one of the elevating lifts 10may be free to rotate, while the remaining set of casters 24 and bearingseat 174 of the other elevating lift 10 may be locked. This allows forangular positioning of one elevating lift 10 with respect to the otherelevating lift 10. In the three-or-more lift configuration of FIG. 9,any desired number of elevating lifts 10 may be freely positionable withrespect to any desired number of fixed elevating lifts 10.

FIGS. 11 and 12 show a stool 200 which uses a stabilizing base similarto that of the embodiment of the elevating lift 10 of FIG. 5. In thestool 200, the platform 70 has been replaced by a conventional stoolseat 270, and the telescoping cage assembly 40 has been replaced by avertical support 240 having opposed upper and lower ends 241, 243,respectively. The upper end 241 is secured to a lower surface of theseat 270, and the lower end 243 is secured to a movable base 221.

Similar to the previous embodiments, an annular collar 218 is slidablymounted about the vertical support 240. A plurality of upper mounts 248and a plurality of lower mounts 252 are secured to the annular collar218. Similar to the previous embodiments, each leg 226 includes an upperbar 244, having opposed upper and lower ends 266, 268, respectively, anda lower bar 246 having opposed upper and lower ends 280, 282,respectively. The upper end 266 of each upper bar 244 is pivotallysecured to a respective one of the plurality of upper mounts 248.Similarly, the upper end 280 of each lower bar 246 is pivotally securedto a respective one of the plurality of lower mounts 252. A hollow leghousing 242 covers the upper and lower bars 244, 246 of each leg 226.Each leg 226 supports a caster 224, the lower ends 268, 282 of the upperand lower bars 244, 246 being respectively pivotally secured to acorresponding caster support 254 of each caster 224.

A plurality of struts 232, each having opposed upper and lower ends 234,236, respectively, are further provided. The lower end 236 of each strut232 is pivotally secured to a corresponding mount 264 on the movablebase 221.

An eccentric collar 214 is slidably mounted about the vertical support240 above the annular collar 218. A plurality of auxiliary mounts 224are secured to the eccentric collar 214. A plurality of auxiliary bars212 are further provided, each auxiliary bar 212 having opposed upperand lower ends 226, 228, respectively. Each upper end 226 is pivotallysecured to a respective one of the plurality of auxiliary mounts 224.Each lower end 228 is pivotally secured to a respective one of thecaster supports 254 of the plurality of casters 224.

In addition to the pivotal attachment of the lower end 228 to the castersupport 254, the lower end 228 may be additionally rotationallyadjustable through rotating connection 230, i.e., the pivotal attachmentof the lower end 228 to the caster support 254 creates rotation of theleg 226 about a horizontal axis during collapse and extension of thelegs 226, but further rotational freedom about the vertical axis ispossible. Rotational linkage 230, which links the lower end 228 to thecaster support 254, drives simultaneous rotation of all casters 224 inparallel, allowing all casters 224 to be simultaneously steered in thesame direction.

As shown in FIG. 12, the eccentric collar 214 preferably includes anupper portion 310 and a lower portion 312. The upper portion 310includes an annular ring to which the auxiliary mounts 224 are secured.The lower portion 312 includes a circular disc 314 to which hollowsupport 316 is attached. The circular disc 314 is disposed within theannular ring of upper portion 310. As shown, the hollow support 316 issubstantially square in cross section. The lower end 243 of the verticalsupport 240 is circular in cross section, and the remainder of thevertical support 240 preferably is substantially square in crosssection. The substantially square portion of the vertical support 240extends through the substantially square hollow support 316 (and acorresponding substantially square opening formed through the circulardisc 314). Thus, the eccentric collar 214 is angularly fixed withrespect to the vertical support 240.

The lower end of the hollow support 316 has a circular rim 318 forrotational engagement with the annular collar 218. Thus, although theeccentric collar 214 is angularly fixed with respect to the verticalsupport 240, the eccentric collar 214 is rotatable with respect to theannular collar 218. Further, the circular lower end 243 of the verticalsupport 240 is extends through a circular opening 320 formed through themovable base 221, allowing the vertical support 240 to be selectivelyrotatable with respect to the movable base 221. Thus, manual rotation ofthe seat 270 and/or the upper portion of the vertical support 240 causesrotation only in the eccentric disc 214 and the auxiliary legs 212. Theannular collar 218 and the movable base 221 are unaffected by manualrotation of the seat 270 and/or the upper portion of vertical support240.

It is to be understood that the elevating lift with a stabilized movablebase is not limited to the specific embodiments described above, butencompasses any and all embodiments within the scope of the genericlanguage of the following claims enabled by the embodiments describedherein, or otherwise shown in the drawings or described above in termssufficient to enable one of ordinary skill in the art to make and usethe claimed subject matter.

We claim:
 1. An elevating lift with a stabilized movable base,comprising: a base having opposed upper and lower surfaces; a housingmounted on the upper surface of the base, the housing having an openupper end, at least one sidewall, and a lower end; a telescoping cageassembly having an upper end and a lower end, the lower end beingmounted on the upper surface of the base secured within the housing; aplatform assembly mounted on the upper end of the telescoping cageassembly; an annular collar slidably mounted about the at least onesidewall of the housing; a plurality of upper mounts disposed on theannular collar; a plurality of lower mounts disposed on the annularcollar; a plurality of legs, each on the legs including: an upper barhaving opposed upper and lower ends, the upper end of the upper barbeing pivotally attached to a respective one of the plurality of uppermounts; a lower bar having opposed upper and lower ends, the upper endof the lower bar being pivotally attached to a respective one of theplurality of lower mounts; and a hollow leg housing covering the upperand lower bars; a plurality of casters having swivel caster heads, eachof the swivel caster heads having the lower end of one of the upper barsand the lower end of one of the lower bars pivotally attached thereto,whereby each of the legs defines a four-bar parallelogram linkagestabilizing the casters, and whereby the base is movable on the casters;and a plurality of struts having opposed upper and lower ends, the upperend of each of the struts being pivotally attached to a central portionof a corresponding one of the plurality of legs, the lower end of eachof the struts being pivotally attached to the lower end of the housing.2. The elevating lift as recited in claim 1, further comprising a linearactuator connected to said annular collar for selectively andcontrollably vertically translating said annular collar with respect tothe housing, thereby extending and retracting the legs to stabilize themovable base.
 3. The elevating lift as recited in claim 1, wherein eachsaid caster further comprises a wheel hub, a lock disk having aplurality of radially extending slots defined therein, and a selectivelyactivated electric motor screw linear actuator having a locking pinmounted thereon so that the screw actuator is selectively extendableinto one of the slots to prevent rotation of the wheel hub and saidcaster.
 4. The elevating lift as recited in claim 1, wherein said basehas a plurality of recesses peripherally formed therein, each of therecesses being aligned with a respective one of the struts.
 5. Theelevating lift as recited in claim 1, further comprising: an eccentriccollar slidably mounted about the housing above the annular collar; arotating cuff mounted about the housing above the eccentric collar, therotating cuff being rigidly attached to the eccentric collar, therotating cuff being selectively rotatable about the housing; a pluralityof auxiliary mounts disposed on the eccentric collar; and a plurality ofauxiliary bars, each of the auxiliary bars having opposed upper andlower ends, the upper end being pivotally attached to a respective oneof the auxiliary mounts, the lower end being attached to a respectiveone of the swivel caster heads.
 6. The elevating lift as recited inclaim 5, further comprising an auxiliary linear actuator for selectivelydriving rotation of the rotating cuff with respect to the housing. 7.The elevating lift with a stabilized movable base as recited in claim 5,wherein the lower end of each said auxiliary bar is further rotatableabout a vertical axis and is rotatably linked to a corresponding one ofthe swivel caster heads in order to steer said casters.